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| United States Patent |
5,307,129
|
|
Miura
, et al.
|
April 26, 1994
|
Image processing apparatus
Abstract
In an image forming apparatus, a toner cartridge is removably set to a
toner supply device and used while being set to the toner supply device,
and the toner cartridge includes a main body with a toner supply port and
a spiral agitator being disposed within the main body and rotated by drive
means.
The apparatus also includes a reserve tank for a toner dispensing section
including a toner container for containing toner supplied from a
cartridge, and a toner supply section for receiving toner from the toner
container and supplying the received toner to a developing unit. The toner
container includes a spiral agitator for supplying toner to the toner
supply section. An auger for transferring toner to the developing unit is
disposed in the toner supply section. A toner transfer power of the spiral
agitator is larger than that of the auger.
An empty detector is disposed at such a location that, unsoiled by toner
leaked from the toner cartridge, the empty sensor can sense, within the
reserve tank, such an amount of toner left in the reserve tank as to allow
the toner to be dispensed a prescribed number of times. A display means is
also provided for displaying an empty state of the reserve tank according
to an empty signal derived from the empty sensor.
| Inventors:
|
Miura; Kanenori (Kanagawa, JP);
Suzuki; Shiro (Kanagawa, JP);
Takahashi; Yasuhito (Kanagawa, JP);
Ono; Masaru (Kanagawa, JP)
|
| Assignee:
|
Fuji Xerox Co., Ltd. (Tokyo, JP)
|
| Appl. No.:
|
766539 |
| Filed:
|
September 27, 1991 |
Foreign Application Priority Data
| Oct 01, 1990[JP] | 2-263443 |
| Oct 01, 1990[JP] | 2-263444 |
| Oct 03, 1990[JP] | 2-265694 |
| Current U.S. Class: |
399/263; 222/DIG.1 |
| Intern'l Class: |
G03G 015/06 |
| Field of Search: |
355/260
222/DIG. 1
|
References Cited
U.S. Patent Documents
| 3724725 | Apr., 1973 | Stauffer | 222/DIG.
|
| 4739907 | Apr., 1988 | Gallant | 222/DIG.
|
| 4744493 | May., 1988 | Ikesue et al. | 222/DIG.
|
| 4924920 | May., 1990 | Bhagwat | 355/260.
|
| 4943830 | Jul., 1990 | Sulenski | 222/DIG.
|
| 5025289 | Jun., 1991 | Guslit et al. | 355/260.
|
| 5084734 | Jan., 1992 | Yoshino et al. | 355/260.
|
Primary Examiner: Grimley; A. T.
Assistant Examiner: Ramirez; Nestor R.
Attorney, Agent or Firm: Finnegan, Henderson, Farabow, Garrett & Dunner
Claims
What is claimed is:
1. A toner cartridge for a toner supply device of an image forming
apparatus, comprising:
a tubular main body having a tubular portion, end walls and a toner supply
port;
a spiral agitator, disposed within the main body, having a free end that
does not contact an inner surface of either of the end walls of the main
body;
drive means for rotating said spiral agitator;
a drive force transmission shaft, integrally formed with the spiral
agitator, having a first end connected to an end of the spiral agitator
opposite to the free end and having a second end coupled to said drive
means, for transmitting a rotating drive force from the drive means to the
spiral agitator; and
a crushing member for crushing lumps of toner formed as a portion of the
drive force transmission shaft near the toner supply port;
wherein said toner cartridge is removably set to the toner supply device
and provides toner to the toner device while being set to the toner supply
device, and
wherein the free end of the spiral agitator is located near the toner
supply port and the second end of the drive force transmission shaft, and
the end of the spiral agitator opposite to the free end is rotatably
supported by the inner surface of one of the end walls of the main body.
2. The toner cartridge according to claim 1, wherein when a load is applied
to the spiral agitator, the spiral agitator decreases in diameter.
3. The toner cartridge according to claim 1, wherein the spiral agitator is
a spirally coiled metal wire.
4. The toner cartridge according to claim 1, wherein the tubular portion of
the main body is made of paper.
5. The toner cartridge according to claim 1, wherein the toner supply port
supplies toner to a reserve tank in a toner dispensing section of an image
processing apparatus.
6. The toner cartridge according to claim 1, wherein said drive means
comprises a motor, a power transmission mechanism connected to the motor,
and a coupling connecting the power transmission mechanism and the drive
force transmission shaft.
7. The toner cartridge according to claim 1, wherein the spiral agitator
contacts the tubular portion of the main body when the spiral agitator is
at rest.
8. The toner cartridge according to claim 1, wherein the crushing member is
triangular and is formed as a portion of the drive force shaft.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a toner supply device with a
toner-contained cartridge of the throwaway type, which is for supplying
toner to a developing unit of an image forming apparatus, and more
particularly to a toner supply device with a throwaway type cartridge
having a spiral agitator.
The present invention also relates to a reserve tank in a toner dispensing
section for supplying toner to a developing unit.
Additionally, the present invention relates to an empty detector of an
image forming apparatus with a reserve tank which receives toner from a
cartridge used being loaded to the apparatus, and more particularly to an
empty detector for an image forming apparatus, which detects an empty
condition of a reserve tank.
In a conventional toner supply device for supplying toner to a developing
unit of a copying machine, a toner box is installed in a main body of a
copying machine. Toner is supplied from the toner box to the developing
unit by means of an auger. When toner is used up in the toner box, the
toner box is pulled out to a toner supply position, and toner contained in
a spare toner bottle is supplied to the toner box. The kinds of toner
supplied are different for the types of the copying machines used. This
makes servicing of the toner supply difficult and complicated. The toner
supply servicing is usually done by a serviceman, for this reason.
The user must call a serviceman every time toner is used up. The user often
encounters a situation where the user calls the serviceman, but he cannot
quickly come for the toner supply service. The user then cannot use the
copying machine until the serviceman arrives. This is very inconvenient
for users.
In the toner supply servicing, the user often experiences that leaked toner
drops fall on the floor on which the machine is located, or stick to
clothes. Use of a cartridge filled with toner, in place of the
conventional toner bottle, has been proposed. In the machine using the
cartridge, when loaded to the machine, the cartridge is set to the toner
box, and a cap is removed from the cartridge. When the cartridge is empty,
the empty or old cartridge is removed and replaced by a new one. This
proposal successfully solves the problem of soiling with the leaked toner.
The toner supply servicing for the machine using the cartridge requires at
least three actions; 1) to set the cartridge to the toner box, 2) to
supply toner, and 3) to remove the cartridge. This is troublesome work.
The serviceman call is still needed for the toner supply work. The problem
as state above still remains unsolved.
If the user, layman, tries to replace the old toner cartridge with a new
one, he will frequently make mistakes in the toner supply servicing. For
example, a toner incompatible with the copying machine under use or an
imitative toner may be set to the toner box of the machine.
Also in a case that the copying machine is left not used for a long time
and accordingly toner is left in an immovable condition for a long time,
the toner will make into lumps within the cartridge. The toner lumps may
cause toner blocking.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above circumstances and
has an object to provide a toner supply device for an image forming
apparatus which solves the problem of the toner blocking taking place
within a cartridge.
According to a first aspect of the invention, there is provided a toner
supply device for an image forming apparatus, comprising a tubular toner
cartridge, which is removably set to the toner supply device and used
while being set to the toner supply device, and a spiral agitator disposed
within the toner cartridge. When the spiral agitator is rotated, toner is
transferred to a toner supply port. Accordingly, the toner blocking is
prevented and the toner is stably and reliably transferred to the port.
The resultant picture is stable and excellent in picture quality.
In the toner supply device of the invention, the toner supply port is
formed at one end of the main body, and the end of the spiral agitator,
which is closer to the toner supply port, is free, and supported by the
tubular main body (only rotation of it is allowed). Generally, toner
blocking tends to occur particularly in the vicinity of the toner supply
port. With the free end of the spiral agitator, which is closer to the
toner supply port, the toner blocking is effectively removed.
Also in the toner supply device, a drive force transmission shaft for
transmitting a rotating drive force from the drive means is provided at
the end of the spiral agitator, which is opposite to the end closer to the
toner supply port, in a state that the shaft is integral with the spiral
agitator. With this structure, when the spiral agitator is rotated so as
to transfer toner toward the toner supply port, and load by the toner is
locally applied to the spiral agitator, the spiral agitator becomes small
in diameter. Therefore, such a situation will never occur that the spiral
agitator touches the inner wall of the tubular main body of the cartridge,
and is locked. In addition, good dispensing of toner is secured. One piece
construction of the drive force transmission shaft and the spiral agitator
leads to a decrease in the number of parts and components, and easy
manufacturing and reduction of cost to manufacture.
Additionally in the toner supply device, a crushing member for crushing
lumps of toner is provided near the toner supply port. Provision of the
toner crushing member prevents the toner blocking in the vicinity of the
toner supply port, and hence results in a stable toner dispensing
operation.
Another object of the invention is to provide a reserve tank for a toner
dispensing section of an image forming apparatus, which provides a stable
dispensing operation even if the apparatus uses the reserve tank as a
medium component for the toner supply to the developing unit.
Yet another object of the invention is to provide a reserve tank for a
toner dispensing section of an image forming apparatus which improves the
manipulation in the toner supply work and protects the inside of the
machine and the machine-located floor against the leaked toner.
A further object of the present invention is to provide a reserve tank for
a toner dispensing section of an image forming apparatus which is free
from the missetting of a toner incompatible with a copying machine under
use or an imitative toner.
According to a second aspect of the invention, there is provided a reserve
tank for a toner dispensing section of an image forming apparatus,
comprising a toner container for containing toner supplied from a
cartridge, and a toner supply section for receiving toner from the toner
container and supplying the received toner to a developing unit. A spiral
agitator for supplying toner to the toner supply section is provided in
the toner container. An auger for transferring toner to the developing
unit is disposed in the toner supply section. A toner transfer power of
the spiral agitator is set to be larger than that of the auger.
Since the toner transfer power of the spiral agitator is larger than that
of the auger, a toner pressure within the reserve tank is maintained
substantially constant, stabilizing the dispensing operation.
The reserve tank may comprise a cover for covering the upper portion of a
reserve tank. The cover includes holder means for holding the toner
cartridge, an opening for leading toner from the toner cartridge into the
reserve tank, and a shutter for opening and closing the opening in
synchronism with the operation of setting the toner cartridge to the
holder means.
The shutter prevents foreign material from entering the reserve tank
through the opening. The shutter is automatically opened and closed when
the cartridge is set, thereby providing easy operation of the shutter.
The shutter is locked at a predetermined position by a lock mechanism, and
is unlocked in synchronism with the operation of setting the cartridge to
the holder means, whereby the shutter is opened and closed.
Accordingly, the missupply of the incompatible toner and imitative toner as
well is prevented.
The reserve tank may comprise a cover for covering the upper portion of a
reserve tank. The cover includes holder means for holding the toner
cartridge, positioning means for positioning the toner cartridge, and an
opening for leading toner from the toner cartridge into the reserve tank.
The cover serves as a toner receptacle, with the holder means being
integral with the positioning means.
With the construction, the toner cartridge is positioned in place by the
positioning means and held by the holder means when it is set. An exact
and easy setting of the toner cartridge is realized.
The reserve tank may also comprise a cover for covering the upper portion
of a reserve tank. The cover includes holder means for holding the toner
cartridge, positioning means for positioning the toner cartridge, and an
opening for leading toner from the toner cartridge into the reserve tank.
The cover further may comprise a toner staying portion being formed near
the opening of the cover.
Since the toner staying portion receives toner leaked from the reserve
tank, the shutter can be smoothly opened and closed, and the toner will
not be sputtered.
Also in the reserve tank, a cover member covering the lower side of the
developing unit and the toner dispensing portion is integral with the
reserve tank.
The cover member reliably receives the toner leaking from a gap between the
developing unit and the toner dispensing portion. Accordingly, the inside
of the machine, the floor, and the like will not be soiled by the leaked
toner.
A further object of the invention is to provide an empty detector in use
with an image forming apparatus for accurately and easily sensing an empty
state of a reserve tank. An additional object of the invention is to
provide an empty detecting method for accurately and readily detecting an
empty state of a reserve tank.
According to a third aspect of the invention, there is provided an empty
detector in use with an image forming apparatus, in which the empty sensor
is disposed at such a position that, unsoiled by toner leaked from the
toner cartridge, the sensor can detect, within the reserve tank, such an
amount of toner left in the reserve tank as to allow the toner to be
dispensed a prescribed number of times. Display means responds to an empty
signal from the toner empty sensor to indicate that the reserve tank is
empty. Accordingly, the empty sensor accurately senses the amount of left
toner, while being unsoiled by the leaked toner. Even after the empty
state of the reserve tank is detected, the developing operation may be
performed the prescribed number of times.
In the empty detector, a spiral agitator for transferring toner is disposed
within the reserve tank, and the spiral agitator is provided with a
cleaning member, which cleans the sensor surface of the empty sensor while
moving across the empty sensor in a non-contact manner. With provision of
the cleaning member, the sensor surface is cleaned, ensuring an high
accuracy of sensing the remaining toner. With no contact of the cleaning
member with the sensor surface, the sensor surface is little worn. Use of
a plurality of cleaning members provides a more efficient cleaning of the
sensor surfaces of different surface areas. Use of the cleaning member
formed of a wire made of resilient material improves a further reliable
cleaning of the sensor surface. If the diameter of the wire ranges between
0.1 mm and 0.5 mm, an improved cleaning operation is obtained.
The empty detector may comprise a display-removal switch for removing a
display visually presenting a message of an empty state of the reserve
tank by the display means, the switch operating in synchronism with the
operations of setting and removing the toner cartridge. With use of the
display removal switch, when a new toner cartridge is set in a prescribed
location, the display of the empty tank is automatically removed. In other
words, the display can be reliably removed without any special
manipulation.
In the empty detector, the display-removal switch may be a two-contact
switch alternately operating when the toner cartridge is set and removed.
In this case, nonvolatile memory means is used for storing an on-state of
the two-contact switch. Means is further provided for detecting a state
change of the on-state of the two-contact switch according to the content
of the memory means, and for removing the tank empty display.
According to a fourth aspect of the invention, there is provided an empty
detecting method which puts into a reserve tank the toner supplied from a
toner cartridge, which is used being set to the reserve tank, feeds the
toner from the reserve tank to a developing unit, detects, by means of an
empty sensor, such an amount of toner left in the reserve tank as to allow
the toner to be dispensed a prescribed number of times, and displays an
empty state of the reserve tank by display means. In the method, a
display-removal switch detects the completion of setting the toner
cartridge, and produces a display-removal signal, and the tank-empty
display by the display means is removed in response to the display-removal
signal.
In the empty detecting method, after the tank empty display by the display
means is removed on the basis of a removal signal from the display removal
signal, the empty sensor is inhibited from sensing the empty state while
the toner is dispensed a prescribed number of times. Therefore, the
erroneous sensing by the empty sensor will not take place.
Also in the empty detecting method, the number of black dispensing
operations is counted from an instant that the display removal switch
outputs a signal, and an amount of the toner left in the toner cartridge
is predicted on the basis of the count.
Additionally, in the empty detecting method, a value of a count
representing the number of the black dispensing operations is reset by the
display-removal signal. Accordingly, an amount of the toner left in the
toner cartridge can be predicted further accurately.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part
of this specification illustrate embodiments of the invention and,
together with the description, serve to explain the objects, advantages
and principles of the invention. In the drawings,
FIG. 1 is a sectional view showing a color copying machine to which a first
embodiment of the invention is applied;
FIG. 2 is an enlarged sectional view showing developing means of the color
copying machine;
FIG. 3 is a cross sectional view showing a toner supply device in the color
copying machine;
FIG. 4 is a longitudinal sectional view showing the toner supply device;
FIG. 5(a) is a front view showing an example of a toner cartridge in the
color copying machine;
FIG. 5(b) is a bottom view showing the toner cartridge;
FIG. 5(c) is a side view of the toner cartridge as viewed from the right
side;
FIG. 5(d) is a sectional view taken on line Vd--Vd in FIG. 5(a);
FIG. 6 is a sectional view of a reserve tank in the color copying machine;
FIG. 7 is a diagram showing the setting of a toner cartridge;
FIGS. 8 through 12 are diagrams showing a second embodiment of the
invention;
FIG. 13 is a sectional view showing a color copying machine to which a
third embodiment of a toner cartridge according to the invention is
applied;
FIG. 14 is an enlarged sectional view showing developing means of the color
copying machine;
FIG. 15 is a cross sectional view showing a toner dispensing portion in the
color copying machine;
FIG. 16 is a longitudinal sectional view showing the toner dispensing
portion;
FIG. 17(a) is a front view showing an example of the toner dispensing
portion in the color copying machine;
FIG. 17(b) is a bottom view showing the toner dispensing portion;
FIG. 17(c) is a side view of the toner dispensing portion as viewed from
the right side;
FIG. 17(d) is a sectional view as viewed in the longitudinal direction;
FIG. 17(e) is a sectional view taken on line VE--VE in FIG. 17(e);
FIG. 17(f) is a perspective view showing the toner dispensing portion;
FIG. 18(a) is a front view showing an example of a cover in the color
copying machine;
FIG. 18(b) is a bottom view showing the cover;
FIG. 18(c) is a side view of the cover as viewed from the right side;
FIG. 18(d) is a sectional view taken on line XVIIID--XVIIID in FIG. 18(a);
FIG. 18(e) is a enlarged view of a portion A in FIG. 18(d);
FIG. 18(f) is a sectional view taken on line XVIIIF--XVIIIF in FIG. 18(a);
FIG. 19(a) is a plan view showing an example of a shutter in the color
copying machine;
FIG. 19(b) is a front view showing the shutter;
FIG. 19(c) is a side view of the shutter as viewed from the right side;
FIG. 20(a) is a sectional view taken on line VIII--VIII in FIG. 15;
FIG. 20(b) is an enlarge sectional view showing a portion B in FIG. 20(a);
FIG. 21 is a sectional view of a reserve tank in the color copying machine;
FIG. 22 is a diagram showing a shutter for opening and closing a toner
supply hole of the reserve tank;
FIG. 23 is a diagram showing the setting of a toner cartridge;
FIG. 24 is a graph showing a dispense rate variation and a toner amount
variation with respect to time;
FIG. 25(a) is a cross sectional view showing a toner supply device to which
a fourth embodiment of a toner cartridge according to the present
invention is applied;
FIG. 25(b) is a partial sectional view of the toner supply device;
FIG. 26(a) is a diagram showing an on state of a first switch of a
2-contact switch;
FIG. 26(b) is a diagram showing an on state of a second switch;
FIG. 27(a) is a front view showing a cleaning member mounted on an
agitator;
FIG. 27(b) is a side view of the cleaning member;
FIGS. 27(c) and 27(d) are diagrams showing how to maintain a prescribed gap
between the cleaning member and an empty sensor; and
FIG. 28 is an explanatory diagram showing the setting of a toner cartridge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will be described in
detail with reference to the accompanying drawings.
FIG. 1 is a sectional view showing a color copying machine to which a first
embodiment of the invention is applied.
As shown in FIG. 1, a color copying machine 1 comprises a main body 2, a
platen 3, provided on the top surface of the main body 2, on which an
original document is placed, an image reader 4, provided under the platen
3, for reading picture information on the original, an image forming unit
5 for forming a prescribed image according to signals from the image
reader 4, a transfer unit 7 for transferring an image formed by the image
forming unit 5 onto paper 6 as image transfer medium, a paper supply
section 8 for supplying the paper 6, and a paper transport section 9 for
transporting paper 6.
The image forming unit 5 includes a photoreceptor 51, first and second
developing means 52 and 53 located adjacent to the photoreceptor 51.
The first developing means 52 is a developing unit with a color,
two-component developer. The second developing means 53 is a developing
unit with a black, two-component developer, and develops a second latent
image by the magnetic brush developing method based on the FX micro-toning
system.
The developing means 52 and 53 are moved to and from the photoreceptor 51
by retract mechanisms, respectively.
The second developing means 53 to which a toner cartridge in a toner supply
device according to the present embodiment is attached, will be described
in more detail.
With the construction as shown in FIG. 2, the second developing means 53
develops a second latent image, which is formed on the photoreceptor 51,
by the magnetic brush developing method based on the FX micro-toning
system. The developing means 53 generally includes a developing roll
(developer bearing member) 1002, a developer agitating means 1003, and a
trimmer plate (trimmer) 1004. The developing roll 1002 is located at an
end portion of a housing 1001, the outer spherical surface of which is
partially exposed to the outside of the housing, through an opening. The
developer agitating means 1003 is disposed on the rear side of the
developing roll 1002 within the housing 1001. The trimmer plate 1004 is
mounted on the top plate of the housing 1001, which is above the
developing roll 1002, and regulates the bristle height of the magnetic
brush of the developer distributed on the developing roll 1002.
Tracking rolls (not shown) are rotatably provided on both sides of the
developing roll 1002. The tracking rolls are brought into contact with the
photoreceptor 51, to maintain a fixed width of a gap between the
developing roll 1002 and the photoreceptor 51.
The agitating means 1003 includes first and second augers 1007 and 1008,
which are parallel to the developing roll 1002 in the axial direction, and
a partitioning plate 1009, erected in the housing 1001, for partitioning
the two augers one from the other. The augers 1007 and 1008 are rotated in
such directions that the developer transfer directions are opposite to
each other. At both end portions of the partitioning wall, openings are
formed through which a region (referred to as a first agitating path 1010)
where the first auger 1007 is disposed communicates with a region
(referred to as a second agitating path 1011) where the second auger 1008
is disposed. Through the openings, the developer circulates through a
route; first agitating path 1010 .fwdarw. second agitating path 1011
.fwdarw. first agitating path 1010.
A paddle wheel 1012 with blades, which longitudinally extend in the axial
direction, is disposed between the developing roll 1002 and the agitating
means 1003. With rotation of the paddle wheel, the developer separated
from the developing roller 1002 is forcibly transferred toward the
agitating means 1003, while the developer mixed and agitated by the
agitating means 1003 is continuously supplied to the developing roll 1002.
A toner supply device 1020, disposed above the first auger 1007 within the
housing 1001, includes a toner cartridge 1021 filed with toner, and a
reserve tank 1022 disposed under the toner cartridge 1021, as shown in
FIGS. 3 and 4.
As shown in FIGS. 5(a) through 5(d), the cartridge 1021 comprises a case
body 1023, a spiral agitator 1024, and a coupling 1025. The case body 1023
includes a tubular portion 1023a made of paper, and resin made end walls
1023b closing both ends of the tubular portion. The spiral agitator 1024
consists of metal wire spirally coiled. The coupling 1025 is coupled with
the spiral agitator 1024. The tubular portion 1023a, when made of paper,
is advantageous in several points. For example, since it can be cut, it is
cut to adjust its length so as to be adaptable for different types of
machines. Since the paper is cheap, cost to manufacture the cartridge 1021
may be considerably reduced.
A toner supply port 1023c for supplying toner to the reserve tank 1022 is
formed in the tubular portion 1023a at one end portion of the case body
1023. The toner supply port 1023c opens to a toner container 1030a as one
of the toner containers of a tank portion 1030 of the reserve tank 1022.
The end 1024a of the spiral agitator 1024, which is closer to the toner
supply port, is free. The other end 1024b, opposite to the end closer to
the toner supply port, is rotatably supported by the inner surface of the
end wall 1023b. A drive force transmission shaft 1024c is continuous to
the end 1024b. The shaft 1024c extends along the axis of revolution
towards the toner supply port 1023c. The distal end of the shaft is
coupled with the coupling 1025, which is rotatably mounted on the center
portion of the right-side end wall 1023b. A toner crushing member 1024d,
shaped like a triangle protrusion, is formed at the portion of the drive
force transmission shaft 1024c, which faces the toner supply port 1023c.
Thus, the spiral agitator 1024 is cantilevered.
As shown in FIGS. 5(a), 5(b), and 5(d), a shutter 1032, mounted on the
cartridge 1021, is circumferentially slidable. The shutter closes the
toner supply port 1023c when the cartridge is not set to the toner supply
device. A flexible sealing means (not shown) for closing the toner supply
port 1023c is stuck on the case body 1023. The sealing means is fixed at
one end to the shutter 1032. When the shutter is circumferentially slid,
the sealing means is peeled off to open the toner supply port 1023c.
As shown in FIG. 4, the toner cartridge 1021 is removably set at a preset
position in a cartridge set portion 1035 provided in the machine main body
2. Specifically, in FIG. 4, the toner cartridge 1021 is axially inserted
toward the cartridge set portion 1035. When the cartridge 1021 reaches a
preset position, the cartridge is turned at a prescribed angle. Then, the
cartridge 1021 is locked, and set to the cartridge set portion 1035. In
this case, when the cartridge 1021 reaches a preset position, a part of
the cartridge 1021 engages with an engaging portion (not shown) of the
reserve tank 1022, to prohibit the rotation of the shutter 1032. At this
time, the shutter 1032 circumferentially slides with respect to the case
body 1023, so that the sealing means is peeled off and the toner supply
port 1023c opens. That is, when the cartridge 1021 is locked and fixedly
set to the cartridge set portion 1035, the toner supply port 1023c is
directed downwardly to open toward the reserve tank 1022.
When the cartridge 1021 is set to the cartridge set portion 1035, the
coupling 1025 of the cartridge 1021 is coupled with another coupling 1025
mounted on a gear 1026a of a power transmission mechanism 1026, which is
provided in the machine main body 2. A rotating drive force generated by
drive means 1027, such as a motor, which is transmitted through the power
transmission mechanism 1026, is transmitted to the end of the spiral
agitator 1024, which is opposite to the toner supply port 1023c.
Accordingly, the spiral agitator 1024 receives the drive force from the
left side in FIG. 5(d). The spiral agitator 1024 rotates in the direction
of an arrow A, and toner flows in the direction of an arrow B, viz.,
toward the toner supply port 1023c, and enters the reserve tank 1022
through the toner supply port 1023c.
Since the toner thus flows, the toner will not form lumps. The rotation of
the toner crushing member 1024d additionally contributes to minimization
of the lumping of the toner. If the toner lumps, the rotating crushing
member crushes the lumps. The rotating direction A of the spiral agitator
1024 is selected so that when load is applied to the spiral agitator 1024,
its diameter will reduce. Accordingly, the spiral agitator 1024 comes in
contact with the inner circumferential surface of the tubular portion
1023a to be locked. This prevents disengagement of the gear 1026a in the
power transmission mechanism 1026.
As illustrated in FIGS. 3 and 6, the reserve tank 1022 includes a tank
section 1030 consisting of toner containers 1030a and 1030b, and a toner
supply section 1031, disposed between the containers 1030a and 1030b, for
supplying toner to the developing means 53. Partition walls 1036 and 1037
are provided partitioning the toner containers 1030a and 1030b, and the
toner supply section 1031. The partition walls 1036 and 1037 extend toward
the left wall 1022b of the body 1022a of the reserve tank 1022, but fail
to reach the wall to form openings 1038 and 1039 between the left wall
1022b and the left ends of the partition walls 1036 and 1037. The
partition walls 1036 and 1037 have respectively openings 1040 and 1041 at
locations deviated from the right ends to the left. Through the openings
1038, 1039, 1040, and 1041, the toner containers 1030a, 1030b, an the
toner supply section 1031 communicate with one another.
Spiral agitators 1042 and 1043 formed of spirally coiled metal lines, for
example, wires are disposed parallel to each other within the toner
containers 1030a and 1030b. The right end 1042a of the spiral agitator
1042 is coupled with a gear shaft 1044, while the left end 1042b is
rotatably supported by the left wall 1022b. The spiral agitator 1042 is
coiled unidirectional. A blade 1045 is mounted on the portion of the
spiral agitator 1042, which faces the opening 1038. The other spiral
agitator 1043 is also supported at both ends in a similar way. In the left
portion of the spiral agitator 1043 with respect to the opening 1041, the
spiral agitator 1043 is coiled in the same direction as the coiled
direction of the spiral agitator 1042, but in the right portion, it is
coiled in the direction opposite to the former. A blade 1046 is mounted to
the portion where the coiling direction is changed, viz., the portion
facing the opening 1041.
A portion of the toner container 1030a on the right side of the opening
1040 serves as a toner introducing portion 1030c. An empty sensor 1047 is
provided on the side wall of the body 1022a at a location relatively to
the left from the position facing the toner supply port 1023c of the
cartridge 1021. The empty sensor 1047 is provided for sensing presence or
absence of toner within the cartridge 1021.
A toner supply hole 1048 for supplying toner to the developing means 53 is
provided at a preset location on the bottom of the toner supply section
1031. Disposed within the toner supply section 1031 is an auger 1049
arranged in parallel to two spiral agitators 1042 and 1043. The auger is
also rotatably supported by the body 1022a as the spiral agitators 1042
and 1043. The coiling directions of the coiled blade of the auger 1049 are
opposite to each other with respect to the supply hole 1048.
In connection with the reserve tank 1022 thus constructed, when the
cartridge 1021 is set to the cartridge set portion 1035, the shutter 1032
slides and the toner supply port 1023c automatically opens concurrently
with the slide. Then, the toner is introduced from the cartridge 1021 to
the toner introducing portion 1030c in the reserve tank 1022, through the
toner supply port 1023c. With rotation of the spiral agitator 1042, the
introduced toner is transferred to the left while at the same time is
sensed by the empty sensor 1047. While the toner is transferred to the
left, new toner is introduced into the toner introducing portion 1030c,
from the cartridge 1021. When the toner reaches the left end of the toner
container 1030a, the toner is transferred, with the blade 1045, toward the
toner supply section 1031, through the opening 1038. A part of the toner
transferred to the toner supply section 1031 is transferred toward the
supply hole 1048 by means of the auger 1049. The toner is further
transferred through the toner supply hole 1048 toward the developing means
53. It is noted here that the toner, after passing the supply hole 1048,
is returned to the supply hole 1048, with the blade of the auger of which
the coiled direction is reversed, as recalled. Accordingly, the toner is
reliably transferred toward the developing means 53, through the supply
hole 1048. The remaining part of the toner transferred to the toner supply
portion 1031 is pushed forwardly by new incoming toner transferred by the
blade 1045, and flows through the opening 1039 to the toner container
1030b. In the toner container 1030b, the toner is transferred toward the
right opening 1041 by means of the spiral agitator 1043. The toner reaches
the opening 1041 and is transferred, by the blade 1046, to the toner
container 1030a openings 1041 and 1040. The toner, if passing the opening
1041, is returned to the opening 1041 by the spiral agitator 1043
reversely coiled. The toner, when entering the toner container 1030a, is
transferred again to the left by the spiral agitator 1042. In this case,
the toner is reliably transferred to the left by the spiral agitator 1042,
so that the toner coming through the opening 1040 will not be transferred
to the left or toward the toner introducing portion 1030c. Consequently,
only the toner supplied from the cartridge 1041 is introduced into the
toner introducing portion 1030c.
In this way, a prescribed amount of toner within the reserve tank 1022 is
transferred from the supply hole 1048 to the developing means 53, while
the remaining toner circulates between the toner containers 1030a and
1030b. The toner circulation prevents the toner from lumping within the
containers 1030a and 1030b.
The volumes of the toner containers 1030a and 1030b are selected such that
2000 to 3000 number of copies can be made till a new cartridge is set
after the cartridge 1021 is empty.
As shown in FIG. 7, a dispenser unit, supported by the main body 2 of the
copying machine, is swung between two positions A and B. The dispenser
unit incorporates the cartridge 1021, cartridge set portion 1035, reserve
tank 1022, power transmission mechanism 1026, and motor drive means 1027.
In the position A as indicated by a solid line and extended laterally in
the main body 2, the cartridge 1021 is set and used. In the position as
indicated by a two-dot chain line and extended vertically in the main body
2 and located outside the main body, the cartridge 1021 is replaced with a
new one. For replacement of the cartridge, the dispenser unit is turned to
the replacing position B. An old cartridge 1021 is removed, and a new
cartridge is set in the cartridge set portion 1035. Thereafter, the
dispenser unit is turned to the position A and fixed thereat.
FIGS. 8 through 12 are sectional views showing other embodiments of the
present invention. In those figures, like reference symbols are used for
designating like or equivalent portions in the figures which were referred
to in the description of the first embodiment.
In the embodiment of FIG. 8, the toner crushing member 1024d is provided at
the free end 1024a of the spiral agitator 1024, which faces the toner
supply port 1023c. With rotation of the spiral agitator 1024, the toner
crushing member 1024d also rotates, so that the toner will not lump and
the lump, if lumped, is crushed.
In the embodiment of FIG. 9, the toner crushing member 1023d is vertically
movably provided in the vicinity of the toner supply port 1023c of the
bottom of the tubular portion 1023a. The toner crushing member 1023d is
constantly biased upwardly by means of energizing means, such as a spring.
When the spiral agitator 1024 comes in contact with it, it is pressed
down. With rotation of the spiral agitator 1024, a contact of the toner
crushing member 1023d with the spiral agitator 1024 moves to the right as
viewed in the drawing. Accordingly, the tone crushing member 1023d rotates
counterclockwise. When the contact of the toner crushing member 1023d with
the spiral agitator 1024 further moves to the right, the spiral agitator
1024 slips out of the toner crushing member 1023d, and is sprung upward by
means of the energizing means. At this time, toner lumps are crushed near
the toner supply port 1023c.
In the embodiment shown in FIG. 10, the toner crushing member is not used.
In the embodiment of FIG. 11, the toner supply port 1023c and the coupling
1025 are distantly disposed at both ends of the cartridge, respectively.
In the embodiments as mentioned above, the toner supply port 1023c and the
coupling 1025 are provided on the same side of the cartridge. The power
transmission shaft 1024c laterally extend within the spiral agitator 1024.
In the instant embodiment, no power transmission shaft 1024c laterally
extends within the spiral agitator 1024. The free end of the spiral
agitator 1024 is positioned closer to the toner supply port 1023c. The
embodiment shown in FIG. 12 is arranged such that the toner supply port
1023c and the coupling 1025 are both located on the same side. Also in
this embodiment, no power transmission shaft 1024c laterally extends
within the spiral agitator 1024. The free end of the spiral agitator 1024
and the toner supply port 1023c are oppositely disposed.
As seen from the foregoing description, in the present invention, the
spiral agitator is provided within the toner cartridge. The provision of
the spiral agitator prevents the blocking phenomenon of toner.
Accordingly, a stable and reliable supply of toner is secured, providing a
high quality of picture.
The end of the spiral agitator closer to the toner supply port is free.
This prominent characteristic effectively suppresses the toner blocking
which tends to occur in the vicinity of the toner supply port.
It is further noted that the rotating drive force of the drive means is
applied from the portion opposite to the toner supply port of the spiral
agitator. With the rotation, the diameter of the spiral agitator becomes
small. Accordingly, it will not be locked, providing an excellent
dispensing of the toner.
Additionally, it is noted that the toner crushing member is provided near
the toner supply port. Use of the toner crushing member greatly
contributes to the removal of the toner blocking near the toner supply
port.
A third embodiment of the present invention will be described in detail
with reference to the accompanying drawings.
FIG. 13 is a sectional view showing a color copying machine to which a
third embodiment of the invention is applied.
As shown in FIG. 13, a color copying machine 1 comprises a main body 2, a
platen 3, provided on the top surface of the main body 2, on which an
original document is placed, an image reader 4, provided under the platen
3, for reading picture information on the original, an image forming unit
5 for forming a prescribed image according to signals from the image
reader 4, a transfer unit 7 for transferring an image formed by the image
forming unit 5 onto paper 6 as image transfer medium, a paper supply
section 8 for supplying the paper 6, a paper transport section 9 for
transporting paper 6, a fixing unit 10 for fixing a toner image that is
transferred on paper by the image forming unit 5, and a discharge tray 11
for receiving paper bearing a toner image fused thereon.
The image forming unit 5 includes a photoreceptor 51, first and second
developing means 52 and 53 located adjacent to the photoreceptor 51. The
first developing means 52 is a developing unit with a color, two-component
developer. The second developing means 53 is a developing unit with a
black, two-component developer.
The developing means 52 and 53 are moved to and from the photoreceptor 51
by retract mechanisms (not shown), respectively.
The second developing means 53 to which a reserve tank in a toner dispense
section according to the present embodiment, will be described in more
detail.
With the construction as shown in FIG. 14, the second developing means 53
develops a second latent image, which is formed on the photoreceptor 51.
The developing means 53 generally includes a developing roll (developer
bearing member) 2002, a developer agitating means 2003, and a trimmer
plate (trimmer) 2004. The developing roll 2002 is located at an end
portion of a housing 2001, the outer spherical surface of which is
partially exposed to the outside of the housing, through an opening. The
developer agitating means 2003 is disposed on the rear side of the
developing roll 2002 within the housing 2001. The trimmer plate 2004 is
mounted on the top plate of the housing 2001, which is above the
developing roll 2002, and regulates the bristle height of the magnetic
brush of the developer distributed on the developing roll 2002.
Tracking rolls (not shown) are rotatably provided on both sides of the
developing roll 2002. The tracking rolls are brought into contact with the
photoreceptor 51, to maintain a fixed width of a gap between the
developing roll 2002 and the photoreceptor 51.
The agitating means 2003 includes first and second augers 2005 and 2006,
which are parallel to the developing roll 2002 in the axial direction, and
a partitioning plate 2007, erected in the housing 2001, for partitioning
the two augers one from the other. The augers 2005 and 2006 are rotated in
such directions that the developer transfer directions are opposite to
each other. At both end portions of the partitioning wall 2007, openings
are formed through which a region (referred to as a first agitating path
2008) where the first auger 2005 is disposed communicates with a region
(referred to as a second agitating path 2009) where the second auger 2009
is disposed. Through the openings, the developer circulates through a
route; first agitating path 2008 .fwdarw. second agitating path 2009
.fwdarw. first agitating path 2008.
A paddle wheel 2010 with blades, which longitudinally extend in the axial
direction, is disposed between the developing roll 2002 and the agitating
means 2003. With rotation of the paddle wheel, the developer separated
from the developing roller 2002 is forcibly transferred toward the
agitating means 2003, while the developer mixed and agitated by the
agitating means 2003 is continuously supplied to the developing roll 2002.
A toner supply device 2011, disposed above the first auger 2005 within the
housing 2001, includes a toner cartridge 2012 filed with toner, and a
reserve tank 2013 disposed under the toner cartridge 2012, as shown in
FIGS. 15 and 16.
As shown in FIGS. 17(a) through 17(d), the cartridge 2012 comprises a case
body 2014, a spiral agitator 2015, and a coupling 2016. The case body 2014
includes a tubular portion 2014a made of paper, and resin made, end walls
2014b closing both ends of the tubular portion. The spiral agitator 2015
consists of metal wire spirally coiled. The coupling 2016 is coupled with
the spiral agitator 2015. The tubular portion 2014a, when made of paper,
is advantageous in several points. For example, since it can be cut, it is
cut to adjust its length so as to be adaptable for different types of
machines. Since the paper is cheap, cost to manufacture the cartridge 2012
may be considerably reduced.
A toner supply port 2014c for supplying toner to the reserve tank 2013 is
formed in the tubular portion 2014a at one end portion of the case body
2014. The toner supply port 2014c opens to a toner container 2017a as one
of the toner containers of a tank portion 2017 of the reserve tank 2013.
The end 2015a of the spiral agitator 2015, which is closer to the toner
supply port 2014c, is free. The other end 2015b, opposite to the end
closer to the toner supply port, is rotatably supported by the inner
surface of the end wall 2014b. A drive force transmission shaft 2015c is
continuous to the end 2015b. The shaft 2015c extends along the axis of
revolution towards the toner supply port 2014c. The distal end of the
shaft is coupled with the coupling 2016, which is rotatably mounted on the
center portion of the right-side end wall 2014b. A toner crushing member
2015d, shaped like a triangle protrusion, is formed at the portion of the
drive force transmission shaft 2015c, which faces the toner supply port
2015c. Thus, the spiral agitator 2015 is cantilevered.
As shown in FIG. 17, a shutter 2018, mounted on the cartridge 2012, is
circumferentially slidable. The shutter closes the toner supply port 1014c
when the cartridge is not set to the toner supply device. As shown, a
guide member 2014d is formed in the circumferential surface of the tubular
member 2014a of the main body 2014. Guide grooves 2014e are
circumferentially formed in the guide member 2014d. Both sides of the
shutter 2018 are bent and the bent portions are slidably inserted into the
guide grooves 2014e. A flexible sealing means (not shown) for closing the
toner supply port 2014c is stuck on the case body 2014. The sealing means
is fixed at one end to the shutter 2018. When the shutter is
circumferentially slid, the sealing means is peeled off to open the toner
supply port 2014c. As shown in FIG. 17(c), an unlock cam 2014f is provided
on a location on the guide member 2014d, which is substantially opposed to
the location of the shutter 2018 as circumferentially viewed.
As shown in FIG. 17(f), first and second positioning means 2019 and 2020
are provided on each end wall 2014b. The first positioning means 2019
protrudes from the circumferential edge of the end wall 2014b, which is
closer to the toner supply port 2014c. The end face of the first
positioning means 2019 is flat. The second positioning means 2020
protrudes from the circumferential edge of the end wall 2014b, which is
far from the toner supply port 2014c, and its end face is flat. As best
shown in FIGS. 17(c) and 17(f), the second positioning means 2020 is
angularly shifted from the first positioning means 2019 by an angle
.alpha., clockwise. The flat end face a.sub.2 of the second positioning
means 2020 is wider than that a.sub.1 of the first positioning means 2019.
The unlock cam 1014f, as shown in FIG. 17(c), is angularly shifted from the
first positioning means 2019 by a prescribed angle .beta., clockwise. The
angle .beta. will be described in detail later.
As shown in FIGS. 15 and 16, the toner cartridge 2021 is removably set at a
preset position in a cartridge set portion 2021 provided in the machine
main body 2. As shown in FIGS. 18(a) through 18(c), the cartridge set
portion 2021 is formed in a cover 2022 for closing an upper opening of the
reserve tank 2013. The cover 2022 is formed, in one piece construction, of
a semitubular frame 2022a for holding the toner cartridge 2012, a side
wall 2022b provided at one end of the frame 2022a, and a mounting portion
2022n fitted on the upper end of the reserve tank 2013.
A rectangular opening 2022c is formed at a location closer to the side wall
2022b of the frame 2022a. As will be described later, through this opening
2022c, toner is supplied from the toner cartridge 2012 to the reserve tank
2013. As shown in FIG. 18(d), a lock 2022d is formed in the vicinity of
the opening 2022c of the frame 2022a. As seen from FIG. 18(e), the lock
2022d includes an arm 2032f circumferentially extending from the frame
2022a within an opening 2022e formed in the frame 2022a, and a lock part
2022g, which at the tip of the arm, protrudes from the inner surface of
the frame 2022a. When the arm 2022f, resiliently deformable, receives a
force in the right direction in the drawing, the lock part 2022g retracts
outwardly beyond the inner circumferential surface of the frame 2022a.
When the force is removed, the lock part moves, by the resilient force,
inwardly beyond the inner circumferential surface.
The opening 2022c of the frame 2022a of the cover 2022 is closed by the
shutter 2023. As shown in FIG. 19, the shutter 2023, semicircular in cross
section, includes a cartridge support 2023a for supporting the tubular
portion 2014a of the toner cartridge 2012, and a shutter portion 2023b
which supports a guide member 2014d of the toner cartridge 2012 and closes
the opening 2022c. A cut-out groove 2023c is present between the support
2023a and the shutter portion 2023b. When the shutter 2023 is set to a
prescribed location of the frame 2022a of the cover 2022, the lock part
2022g of the lock 2022d is fitted into this groove 2023c. This will be
described later in detail.
The inner circumferential surfaces of both the ends of the shutter portion
2023b consist of circumferentially extending, thinned parts 2023d. As
shown in FIG. 20(a), each thinned part 2023d is fitted in a guide groove
2022j of the side wall of a concave portion 2022i elongated
circumferentially along the guide member 2022h, which is provided near the
opening 2022c of the frame 2022a. In this way, the shutter 2023 is
assembled into the frame 2022a, while being circumferentially slidable. In
a state that the shutter 2023 is assembled into the frame 2022a, the
cut-out groove 2023c opens to the left with respect to the cover 2022
shown in FIG. 18(a). When the shutter 2023 is at the leftmost position
where it completely closes the opening 2022c, as indicated by a two-dot
chain line in FIG. 19, the lock 2022d is fitted into the cut-out groove
2023c. In this state, the shutter 2023 is circumferentially immovable,
maintaining the closing of the opening 2022c. Foreign materials such as
dust and particle will not enter the reserve tank 2013, through the
opening 2022c.
As shown in FIGS. 18(a) and 18(f), a toner stay portion 2022p is formed in
the frame 2022a, near the opening 2022c. The toner stay portion 2022p
receives toner trailed by the shutter 2023 when it is opened and closed,
and toner and the like leaked through a gap between the guide groove 2022j
and the thinned parts 2023d of the shutter 2023. The toner is possibly
leaked through the gap from the reserve tank 2013 in the direction of an
arrow shown in FIG. 20(b), by a pressure by which the toner is kept under
a fixed pressure within the reserve tank. Since the toner coming into the
frame 2022a of the cover 2022 is thus received by the toner stay portion
2022p, the toner will not be sputtered within the frame 2022a, and such a
situation will not take place that the toner filling the guide groove
2022j hinders the smooth closing and opening of the shutter 2033.
As shown in FIG. 18(c), a circular hole 2022k is formed in the side wall
2022b. A tubular protrusion 2014g formed in the side wall 2014b of the
toner cartridge 2012 is inserted into the circular hole 2014b, when the
toner cartridge 2012 is set. The cover 2022 thus constructed is set on the
reserve tank 2013 in a state that the side wall 2022b of the cover is
positioned on the side closer to a power transmission mechanism 2039 to be
given later (on the ride side in FIG. 16). The toner cartridge 2012 is
precisely positioned for the reserve tank 2013 and a drive gear 2039a of
the power transmission mechanism, and set because the frame 2022a, side
wall 2014b, and the mounting portion 2022n, which support the toner
cartridge 2012 make up one piece. Since the toner cartridge 2012 is thus
positioned and held by the frame 2022a, the setting of the toner cartridge
2012 is easy.
The one piece construction of the frame 2022a, side wall 2014b, and the
mounting portion 2022n forms the cover as a toner receive container.
Specifically, the semitubular frame 2022a and the side wall 2014b
cooperate to form a container. With the construction, if toner
unintentionally drops, the toner is completely received by the container
before it enters the inside of the machine.
The prescribed angle .beta. between the first positioning means 2019a.sub.1
and the unlock cam 2014f will be described. The angle .beta. is selected
to be such a value that when the planar surface of the first positioning
means 2019a.sub.1 is directed upwardly and then horizontally, the unlock
cam 2014f axially faces the cut-out groove 2023c. Accordingly, when, after
the toner cartridge 2012 is set to the cartridge set portion 2021, the
toner cartridge 2012 is axially moved toward the side wall 2022b, while
the first positioning means 2019a.sub.1 is held horizontally, the unlock
cam 2014f enters the cut-out groove 2023c. Then, the lock 2022d having
been fitted into the cut-out groove 2023c is pushed by the unlock cam
2014f and gets out of the groove 2023c.
As illustrated in FIGS. 15 and 16, and 21, the reserve tank 2013 includes a
tank section 2017 consisting of toner containers 2017a and 2017b, and a
toner supply section 2024, disposed between the containers 2017a and
2017b, for supplying toner to the developing means 53. Partition walls
2025 and 2026 are provided partitioning the toner containers 2017a and
2017b, and the toner supply section 2024. As shown in FIG. 21, the
partition walls 2025 and 2026 extend toward the left wall 2013b of the
body 2013a of the reserve tank 2013, but fail to reach the wall to form
openings 2027 and 2028 between the left wall 2013b and the left ends of
the partition walls 2025 and 2026. The partition walls 2025 and 2026 have
respectively openings 2029 and 2030 at locations deviated from the right
ends to the left. Through the openings 2027, 2028, 2029, and 2030, the
toner containers 2017a, 2017b, an the toner supply section 2024
communicate with one another.
Spiral agitators 2031 and 2032 formed of spirally coiled metal lines, for
example, wires are disposed parallel to each other within the toner
containers 2017a and 2017b. The right end 2031a of the spiral agitator
2031 is coupled with a gear shaft 2033, while the left end 2031b is
rotatably supported by the left wall 2013b. The spiral agitator 2031 is
coiled unidirectional. A blade 2034 is mounted on the portion of the
spiral agitator 2031, which faces the opening 2027. The other spiral
agitator 2032 is also supported at both ends in a similar way. In the left
portion of the spiral agitator 2032 with respect to the opening 2030, the
spiral agitator 2032 is coiled in the same direction as the coiled
direction of the spiral agitator 2031, but in the right portion, it is
coiled in the direction opposite to the former. A blade 2035 is mounted to
the portion where the coiling direction is changed, viz., the portion
facing the opening 2030.
A portion of the toner container 2017a on the ride side of the opening 2029
serves as a toner introducing portion 2017c. An empty sensor 2036 is
provided on the side wall of the body 2013a at a location relatively to
the left from the position facing the toner supply port 2014c of the
cartridge 2012 in FIG. 21. The empty sensor 2036 is provided for sensing
presence or absence of toner within the cartridge 2012.
A toner supply hole 2037 for supplying toner to the developing means 53 is
provided at a preset location on the bottom of the toner supply section
2024. Disposed within the toner supply section 2024 is an auger 2038
arranged in parallel to two spiral agitators 2031 and 2032. The auger is
also rotatably supported by the body 2013a as the spiral agitators 2031
and 2032. The coiling directions of the coiled blade of the auger 2038 are
opposite to each other with respect to the supply hole 2037.
In connection with the reserve tank 2013 thus constructed, when the
cartridge 2012 is set to the cartridge set portion 2026, the shutter 2018
slides and the toner supply port 2014c automatically opens concurrently
with the sliding operation. Then, the toner is introduced from the
cartridge 2012 to the toner introducing portion 2017c in the reserve tank
2013, through the toner supply port 2014c and the opening 2022c. With
rotation of the spiral agitator 2031, the introduced toner is transferred
to the left while at the same time is sensed by the empty sensor 2036.
While the toner is transferred to the left, new toner is introduced into
the toner introducing portion 2017c, from the cartridge 2012. When the
toner reaches the left end of the toner container 2017a, the toner is
transferred, with the blade 2034, toward the toner supply section 2024,
through the opening 2027. A part of the toner transferred to the toner
supply section 2024 is transferred toward the supply hole 2037 by means of
the auger 2038. The toner is further transferred through the toner supply
hole 2037 toward the developing means 53. It is noted here that the toner,
after passing the supply hole 2037, is returned to the supply hole 2037,
with the blade of the auger of which the coiled direction is reversed, as
recalled. Accordingly, the toner is reliably transferred toward the
developing means 53, through the supply hole 2037.
The remaining part of the toner transferred to the toner supply section
2024 is pushed forwardly by new incoming toner transferred by the blade
2034, and flows through the opening 2028 to the toner container 2017b. In
the toner container 2017b, the toner is transferred toward the right
opening 2030 by means of the spiral agitator 2032. The toner reaches the
opening 2030 and is transferred, by the blade 2035, to the toner container
2017a through the openings 2030 and 2029. The toner, if passing the
opening 2030, is returned to the opening 2030 by the spiral agitator 2032
reversely coiled. The toner, when entering the toner container 2017a, is
transferred again to the left by the spiral agitator 2031. In this case,
the toner is reliably transferred to the left by the spiral agitator 2031,
so that the toner coming through the opening 2029 will not be transferred
to the left or toward the toner introducing portion 2017c. Consequently,
only the toner supplied from the cartridge 2012 is introduced into the
toner introducing portion 2017c.
In this way, a prescribed amount of toner within the reserve tank 2013 is
transferred from the supply hole 2037 to the developing means 53, while
the remaining toner circulates between the toner containers 2017a and
2017b. The toner circulation prevents the toner from lumping within the
containers 2017a and 2017b.
In this embodiment, the numbers of turns and revolutions of the spiral
agitator 2031 and the auger 2038 are selected so that a toner transfer
force of the spiral agitator of 2031 is larger than that of the auger
2038. Accordingly, the amount of toner transferred by the spiral agitator
2031 is smaller than that transferred to the toner supply hole 2037 by the
auger 2038. When the toner is transferred under this condition, the toner
is pressed against the toner supply section 2024 by the spiral agitator
2031, resulting in increase of the toner pressure. When the toner pressure
reaches a fixed pressure, the pressed toner will pass through the hollow
of the spiral agitator 2031 even if the spiral agitator 2031 will supply
further toner thereto, so that the toner pressure fails to increase in
excess of the fixed toner pressure. In this way, the toner pressure of the
toner supplied to the toner supply section 2024 is kept substantially
constant, so that the amount of toner supplied from the toner supply hole
2037 to the developing unit is also kept substantially constant. As a
consequence, the dispensing operation is stable and a density of the
resultant picture is also stable.
The volumes of the toner containers 2017a and 2017b are selected such that
2000 to 3000 number of copies can be made till a new cartridge is set
after the cartridge 2012 is empty.
As shown in FIGS. 15 and 16, the shutter 2042 is provided on the outer
circumferential surface of the toner supply section 2024 in the reserve
tank 2013, while covering the toner supply hole 2037. As best illustrated,
the shutter 2042 is formed of a fan-shaped plate 2042a. The fan-shaped
plate 2042a may be swung about its center fixed to the bottom outer wall
of the reserve tank 2013. The shutter 2042 is biased to one side by bias
means, such as a spring. An opening 2042c, which resembles the toner
supply hole 2037 of the reserve tank 2013, is formed in the plate 2042a.
When for replacement of the toner cartridge 2012, the reserve tank 2013 is
sprung out of the main body 2 of the copying machine as will subsequently
be described, the shutter 2042 is turned, by the spring, to close the
toner supply hole 2037. When the reserve tank 2013 shown in FIGS. 15 and
16 is set to the main body 2, the shutter 2042 engages with an engaging
part 2044b of a tubular member 2044 of the agitating means 43, and turns
resisting the spring force till the opening 2042c is aligned with the
toner supply hole 2037 of the reserve tank 2037. In this state of the
reserve tank 2013 being set, the toner supply hole 2037 is opened to
communicate with a toner introducing port 2044a of the tubular member
2044. With use of the shutter 2042, no toner drops from the reserve tank
2013 when the toner cartridge is replaced.
A cover member 2043 is provided as an integral part on the bottom, outer
surface of the reserve tank 2013. The bottom 2043a of the cover member is
located under the reserve tank 2013. The bottom 2043a receives toner,
which drops from a joint part of the reserve tank 2013 and the tubular
member 2044 of the agitating means 53, when the toner cartridge is
replaced. Accordingly, the inside of the main body 2 of the copying
machine 1 and the floor on which the machine 1 is located will not be
soiled with the toner. The lower end of the cover member 2043 is supported
by the main body 2 (not shown), so that it is set at a fixed vertical
position, and the weight of the dispenser unit 2041 will not be applied to
the developing unit.
As shown in FIG. 23, a dispenser unit, supported by the main body 2 of the
copying machine, is swung between two positions A and B. The dispenser
unit incorporates the cartridge 2012, cartridge set portion 2021, reserve
tank 2013, power transmission mechanism 2039, and motor drive means 2040.
In the position A as indicated by a dashed line and extended laterally in
the main body 2, the cartridge 2012 is set and used. In the position as
indicated by a solid line and extended vertically in the main body 2 and
located outside the main body, the cartridge 2012 is replaced with a new
one. For replacement of the cartridge, the dispenser unit 2041 is turned
to the replacing position B. An old cartridge 2012 is removed, and a new
cartridge is set in the cartridge set portion 2026. Thereafter, the
dispenser unit is turned to the position A and fixed thereat.
Description to follow is how the toner cartridge 2012 is set to the
cartridge set portion 2021. As shown in FIG. 23, a user first turns the
dispenser unit 2041 to the replacing position B, and locates the toner
cartridge 2012 on the cartridge set portion 2021 in a state that the first
positioning means 2019 of the cartridge is positioned above and directed
horizontally. In this state, the toner cartridge 2012 is axially moved
forwardly (to the right in FIG. 16).
If the toner cartridge 2012 is a toner cartridge designed to be used
exclusively for the copying machine under discussion, the unlock cam 2014f
of the toner cartridge 2012 is placed facing the cut-out groove 2023c, and
the unlock cam 2014f is fitted into the cut-out groove 2023c. Accordingly,
the toner cartridge 2012 is allowed to move up to a preset position on the
axial path along which the tubular protrusion 2014g is fitted into the
circular hole 2022k of the cover 2022. If the cartridge containing the
toner incompatible with the copying machine under used or the imitative
toner, the unlock cam 2014f is placed not facing the cut-out groove 2023c.
Accordingly, the unlock cam 2014f cannot be fitted into the cut-out groove
2023c, and hence the toner cartridge cannot be moved up to the preset
position. Thus, setting such cartridges to the cartridge set portion 2021
is rejected. In other words, the user will not set an incorrect toner
cartridge to the cartridge set portion.
When the unlock cam 2014f is inserted into the cut-out groove 2023c, the
cam 2014f pushes the lock 2022d to expel it out of the cut-out groove
2023c. Then, the shutter 2023 is slidable in the circumferential
direction. In this state, if the toner cartridge 2012 is turned
counterclockwise in FIG. 15 (the user turns it clockwise), the end 2014h
of the guide member 2014d closer to the guide member 2014d comes in
contact with the end 2023e of the cartridge support 2023a closer to the
shutter portion 2023b. Accordingly, the shutter 2023 turns together with
the toner cartridge 2012. With rotation of the shutter 2023, the opening
2022c of the cover 2022 is opened. One end 2018a of the shutter 2018 of
the toner cartridge 2012 engages with the engaging part 2022m. As a
result, if the toner cartridge 2012 is turned, the shutter 2018 will not
turn together with the cartridge. In other words, the shutter 2018 turns
relative to the toner cartridge 2012, so that the toner supply port 2014c
is opened. In this way, both the shutters 2018 and 2023 turn in connection
with the turn of the cartridge 2012, and the toner supply port 2014c and
the opening 2022c automatically open. When the toner cartridge 2012 is
turned, the guide groove 2014e forming part of the guide member 2014d is
fitted into the concave portion 2022i of the guide member 2022h. The
result is that the toner cartridge 2021 is immovable in the axial
direction.
The toner cartridge 2012 is then turned at a prescribed angle .alpha.. The
second positioning means 2020 is horizontally postured, so that the toner
cartridge 2012 is set in place. When the toner cartridge 2012 is set in
place, the toner supply hole 2014c and the opening 2022c are both opened.
Accordingly, toner is introduced from the toner cartridge 2012 into the
toner introducing portion 2017c of the reserve tank 2017, through the
toner supply hole 2014c and the opening 2022c. Finally, the dispenser unit
2041 is turned to set the toner cartridge 2012 to the position A. Here,
the setting of the toner cartridge is completed.
When the toner in the cartridge 2012 is used up and the cartridge must be
replaced with a new one, a user turns the dispenser unit 2041 to set the
cartridge 2012 to the replacing position B. Then, he turns the cartridge
2012 till the first positioning means 2019 is set horizontally in FIG. 15.
In this state, the guide member 2014d slips out of the concave portion
2022i of the guide member 2022h, and the shutter 2023 turns to open the
opening 2022c. The shutter 2018 also moves relative to the toner cartridge
to close the toner supply port 2014c.
Then, the toner cartridge 2012 is axially moved to the left in FIG. 16, and
then the toner cartridge 2012 may be removed. With the movement of the
toner cartridge 2012, the unlock cam 2014f gets out of the cut-out groove
2023c, and the lock 2022d is fitted into the groove 2023c. The result is
that the shutter 2023 is locked to be immovable in the circumferential
direction. The user discards the empty toner cartridge and sets a new
toner cartridge 2012 filled with toner. The setting operation is the same
as mentioned above, and hence no further description will be given here.
As seen from the foregoing description, in the present invention, a toner
transfer force of the spiral agitator 2031 is larger than that of the
auger. Accordingly, the toner pressure within the reserve tank is kept
substantially constant, providing a stable dispensing operation.
Further, foreign materials will not enter the reserve tank through the
opening of the cover. The shutter is automatically opened and closed when
the toner cartridge is set, providing an easy operation.
The shutter is unlocked only when a correct toner cartridge is used. In
other words, setting of the toner incompatible with the copying machine
under use or the imitative toner to the machine, is rejected.
In loading the toner cartridge, the cartridge is automatically set in place
by the positioning means and held in the cover holder. Accordingly, the
toner cartridge can be loaded in an exact and simple manner.
The toner leaked from the reserve tank is received by the toner staying
portion. The problems of the unsmooth operation of the shutter and the
sputtering of toner, which are caused by the leaked toner, can be solved.
The toner dropping from a gap between the developing unit and the toner
dispenser unit is received by the cover member, so that it will not soil
the machine inside and the floor on which the machine is located.
A fourth embodiment of the invention will be described with reference to
the accompanying drawings. In the figures to be referred to in the
following description, like reference symbols are used for designating
like or equivalent portions in FIGS. 13, 14, and 16 through 21 used for
the description of the third embodiment.
As shown in FIGS. 25(a) and 25(b), the cover 2022 is provided with a
two-contact switch 3042. As shown in FIG. 26, the two-contact switch 3042
includes first and second cams 3042b and 3042c fixed to a rotating shaft
3042a, and first and second switches 3042d and 3042e which are
respectively turned on and off by the first and second cams 3042b and
3042c. The first and second cams 3042b and 3042c are angularly shifted by
180.degree.. As shown in FIG. 25(a), when the first cam 3042b is at the
bottom position, a cam follower 3042f moves down, to turn on the first
switch 3042b and to turn off the second switch 3042c. As shown in FIG.
25(b), the second cam 3042c is at the bottom position, a cam follower
3042g moves down, to turn on ff the second switch 3042c and to turn off
the first switch 3042b.
The rotating shaft 3042a is coupled with a gear 3042h by way of a one-way
clutch, not shown. When the rotating shaft 3042a rotates in one direction,
the gear 3042h is fixed to the shaft 3042a through the action of the
one-way clutch. A rotation of the gear 3024h is transferred to the
rotating shaft 3042a, and the first and second cams 3042b and 3042c. When
the rotating shaft 3042a rotates in the other direction, the gear 3042h is
free from the shaft 3042a. The rotation of the gear 3024h is not
transferred to the rotating shaft 3042a, and the first and second cams
3042b and 3042c.
As shown in FIGS. 25(a) and 25(b), the gear 2042h is in mesh with a gear
3023f mounted on the shutter 3023. In FIG. 25(a), when the shutter 3023
rotates counterclockwise, i.e., in the direction to set the toner
cartridge 3012, the gear 3042h rotates clockwise (corresponds to one
direction as mentioned above), thereby to turn the rotating shaft 3042a,
and the first and second cams 3042b and 3042c, through the one-way clutch.
As a result, the on and off states of the first and second switches 3042d
and 3042e are exchanged with each other.
When the shutter 3023 rotates clockwise, i.e., in the direction to remove
the toner cartridge 3012, the gear 3042h rotates counterclockwise
(corresponds to the other direction as mentioned above), so that the
one-way clutch shuts off the transmission of the rotation of the gear
3042h to the rotating shaft 3042a. Under this condition, the first and
second cams 3042b and 3042c will not turn, and the on and off states of
the first and second switches 3042d and 3042e remain as they are.
As illustrated in FIGS. 15 and 16, and 21, the reserve tank 2013 includes a
tank section 2017 consisting of toner containers 2017a and 2017b, and a
toner supply section 2024, disposed between the containers 2017a and
2017b, for supplying toner to the developing means 53. Partition walls
2025 and 2026 are provided partitioning the toner containers 2017a and
2017b, and the toner supply section 2024. As shown in FIG. 21, the
partition walls 2025 and 2026 extend toward the left wall 2013b of the
body 2013a of the reserve tank 2013, but fail to reach the wall to form
openings 2027 and 2028 between the left wall 2013b and the left ends of
the partition walls 2025 and 2026. The partition walls 2025 and 2026 have
respectively openings 2029 and 2030 at locations deviated from the right
ends to the left. Through the openings 2027, 2028, 2029, and 2030, the
toner containers 2017a, 2017b, an the toner supply section 2024
communicate with one another.
Spiral agitators 2031 and 2032 formed of spirally coiled metal lines, for
example, wires are disposed parallel to each other within the toner
containers 2017a and 2017b. The right end 2031a of the spiral agitator
2031 is coupled with a gear shaft 2033, while the left end 2031b is
rotatably supported by the left wall 2013b. The spiral agitator 2031 is
coiled unidirectional. A blade 2034 is mounted on the portion of the
spiral agitator 2031, which faces the opening 2027. The other spiral
agitator 2032 is also supported at both ends in a similar way. In the left
portion of the spiral agitator 2032 with respect to the opening 2030, the
spiral agitator 2032 is coiled in the same direction as the coiled
direction of the spiral agitator 2031, but in the right portion, it is
coiled in the direction opposite to the former. A blade 2035 is mounted to
the portion where the coiling direction is changed, viz., the portion
facing the opening 2030.
The portion of the toner container 2017a on the ride side of the opening
2029 is used as the toner introducing portion 2017c. This toner
introducing portion faces the tone supply port 2014c of the toner
cartridge 2012. In FIG. 21, the location on the left side of the side wall
of the body 2013a of the reserve tank with respect to the location facing
the toner supply port 2014c, is not soiled with the leak toner, which
would take place at the time of replacement of the toner cartridge 2012.
The empty sensor 3036 is provided at such a position as to detect the
amount of toner left in the reserve tank with which 2 to 3 KC copies (2000
to 3000 times) are possible. Placement of the empty sensor 3036 at such a
position eliminates an erroneous sensing of toner, which is due to the
leak toner, and allows 2 KC (2000 times) copies after the empty of the
reserve tank is sensed.
When the empty sensor 3036 senses the empty state consecutively 10 times in
a black copy mode, control decides that the reserve tank is empty, and
continues the sensing of the empty state till the empty sensing is
removed. In this case, if the power source of the copying machine is
turned off in the black copy mode, the empty sensing operation continues.
Such a definition of the empty sensing can prevent the empty sensor 3036
from erroneously operating. If the empty sensor 3036 senses an empty state
of the reserve tank on the basis of the definition, a display window on
the control panel of the copying machine 1 presents a message "Supply
toner". If 2000 copies are performed after the empty message is presented,
the machine 1 is shut down. In this state, the display presents messages
"Cannot operate for copy" and "Supply toner" or a flashing indication.
As shown in FIGS. 21 and 27(a), a pair of cleaning members 3034 are
angularly disposed angularly separated by 180.degree. at a location facing
the empty sensor 3036 of the spiral agitator 2031. The cleaning members
are provided for cleaning, to some extend, toner attached to the sensor
surface of the sensor 3036. Each cleaning member 3034, shaped like a
trapezoid, is formed of a resilient wire of 0.1 to 0.5 mm in diameter made
of nonmagnetic Sus, such as piano wire. When the wire diameter is less
than 0.1 mm, it is difficult to handle the cleaning wires 3043, and the
wires are readily bent by toner weight to lose their cleaning function.
When the diameter is larger than 0.5 mm, the cleaning members 3043 are
repeatedly deformed with the rotation of the agitator, and extremely are
cut. It is for this reason that the diameter should be set within the
above range of figures. With use of wires for the cleaning members 3034,
the wires pass through the toner when the agitator rotates, and will carry
the toner. In a state that a sufficient amount of toner is left, the
cleaning members will not wipe the toner out of the sensor surface.
Accordingly, the erroneous sensing by the empty sensor 3036 will not take
place.
As shown in FIG. 27(b), the cleaning members 3043 each extend in the
tangential direction of the agitator and the direction opposite to the
rotating direction. Both ends of each member are mounted to the spiral
agitator 2031. The cleaning members are each disposed such that the linear
part of it faces the sensor surface of the empty sensor 3036, with a space
of 0 to 0.5 mm between them. In one of the constructions to maintain the
space, as shown in FIGS. 27(c) and 27(d), a pair of projections 3044 of 0
to 0.5 mm high are provided on both sides of the sensor surface of the
empty sensor 3036. The projections 3044 are oriented to cross the moving
direction of the cleaning members 3043. In another construction, as shown
in FIG. 27(e), the empty sensor 3036 is disposed such that the sensor
surface is backwardly separated from the inner surface of the side wall of
the body 2013a, by 0 to 0.5 mm. It is evident that another suitable
construction is available for the maintenance of the gap.
With the construction as stated above, the cleaning members 3034 can make
clean the sensor surface in a noncontact manner. The cleaning members 3043
will not rub the sensor surface, thereby not to wear off the sensor
surface. The extension of the cleaning members 3043 in the tangential
direction of the agitator and in the direction opposite to the rotating
direction, ensures a satisfactory strength of the cleaning members 3043.
Two or more cleaning members 3043 may obviously be used.
In a case where after the empty sensor 3036 senses an empty state of the
reserve tank, and "Supply toner" is displayed on the control panel, a user
replaces the old cartridge with a new one, the display of the message must
be lit off. At the time of toner cartridge replacement, the user sometimes
turns off the power switch of the copying machine 1. It is to cope with
the situations that the first and second switches 3042d and 3042e are
provided.
In the embodiment, the on and off states of the first and second switches
3042d and 3042e are exchanged with each other every time the toner
cartridge 2012 is replaced. A switch being in an on state is constantly
stored in a nonvolatile memory. When an old toner cartridge is removed for
the cartridge replacement, the memory has stored the memory being in an on
state immediately before the removal of the cartridge.
In practical use, the user sometimes turns off the power switch in a state
that an old toner cartridge is removed, but a new tone cartridge is not
yet set. In this case, the message "Supply toner" is still present on the
control panel. The message teaches that the cartridge replacement is
improper. When the user turns on the power switch after a new toner
cartridge is set, the on-state switch is changed to another one in
synchronism with the loading operation of the cartridge. Then, the switch
in the memory is changed and the message "Supply toner" disappears on the
display.
After a new toner cartridge is loaded and the message of "Supply toner"
disappears, the empty sensor 3036 is inhibited from sensing an empty state
of the reserve tank while copying operations are performed 1000 times. The
empty sensor, if so set, will not sense an empty state of the reserve tank
before a sufficient amount of toner is supplied to the reserve tank after
a new toner cartridge is loaded.
The empty sensor 3036 senses an empty state of the reserve tank 2013, and
cannot sense an amount of toner left in the toner cartridge 2012. To know
an approximate time of cartridge replacement, however, it is desirable to
predict an amount of toner left in the toner cartridge 2012. To this end,
the present embodiment employs the following technique to predict the
amount of toner left in the cartridge.
The predicting technique is base on the fact that the number of black
copies is determined by an amount of toner contained in the toner
cartridge 2012, and takes a substantially fixed value (e.g., 20 KC).
Specifically, the number of black copies is counted, and an amount of tone
left in the toner cartridge 2012 is predicted using a count obtained. In
this case, the copying machine counts the number of black copies, and the
result of count is stored in the diag. of the machine. A serviceman reads
its count, to check the amount of left toner. When the count is
approximate to 20 KC, he tells the user that the replacement of the toner
cartridge is needed in near future. The count of the number of copies is
reset when a new toner cartridge is set, that is, when the switch to be
turned on is changed. For the new toner cartridge, the machine starts to
count from 0, again.
A toner supply hole 2037 for supplying toner to the developing means 53 is
provided at a preset location on the bottom of the toner supply section
2024. Disposed within the toner supply section 2024 is an auger 2038
arranged in parallel to two spiral agitators 2031 and 2032. The auger is
also rotatably supported by the body 2013a as the spiral agitators 2031
and 2032. The coiling directions of the coiled blade of the auger 2038 are
opposite to each other with respect to the supply hole 2037.
In connection with the reserve tank 2013 thus constructed, when the
cartridge 2012 is set to the cartridge set portion 2026 to be ready for
use, the shutters 2018 and 2023 slide and the toner supply port 2014c
automatically opens concurrently with the sliding operation. Then, the
toner is introduced from the cartridge 2012 to the toner introducing
portion 2017c in the reserve tank 2013, through the toner supply port
2014c and the opening 2022c. With rotation of the spiral agitator 2031,
the introduced toner is transferred to the left while at the same time is
sensed by the empty sensor 2036. While the toner is transferred to the
left, new toner is introduced into the toner introducing portion 2017c,
from the cartridge 2012. When the toner reaches the left end of the toner
container 2017a, the toner is transferred, with the blade 2034, toward the
toner supply section 2024, through the opening 2027. A part of the toner
transferred to the toner supply section 2024 is transferred toward the
supply hole 2037 by means of the auger 2038. The toner is further
transferred through the toner supply hole 2037 toward the developing means
53. It is noted here that the toner, after passing the supply hole 2037,
is returned to the supply hole 2037, with the blade of the auger of which
the coiled direction is reversed, as recalled. Accordingly, the toner is
reliably transferred toward the developing means 53, through the supply
hole 2037. The remaining part of the toner transferred to the toner supply
section 2024 is pushed forwardly by new incoming toner transferred by the
blade 2034, and flows through the opening 2028 to the toner container
2017b. In the toner container 2017b, the toner is transferred toward the
right opening 2030 by means of the spiral agitator 2032. The toner reaches
the opening 2030 and is transferred, by the blade 2035, to the toner
container 2017a through the openings 2030 and 2029. The toner, if passing
the opening 2030, is returned to the opening 2030 by the spiral agitator
2032 reversely coiled. The toner, when entering the toner container 2017a,
is transferred again to the left by the spiral agitator 2031. In this
case, the toner is reliably transferred to the left by the spiral agitator
2031, so that the toner coming through the opening 2029 will not be
transferred to the left or toward the toner introducing portion 2017c.
Consequently, only the toner supplied from the cartridge 2012 is
introduced into the toner introducing portion 2017c.
In this way, a prescribed amount of toner within the reserve tank 2013 is
transferred from the supply hole 2037 to the developing means 53, while
the remaining toner circulates between the toner containers 2017a and
2017b. The toner circulation prevents the toner from lumping within the
containers 2017a and 2017b.
The volumes of the toner containers 2017a and 2017b are selected such that
2000 to 3000 number of copies can be made till a new cartridge is set
after the cartridge 2012 is empty.
As shown in FIG. 28, a dispenser unit 2041, supported by the main body 2 of
the copying machine, is swung between two positions A and B. The dispenser
unit 2041 incorporates the cartridge 2012, cartridge set portion 2021,
reserve tank 2013, power transmission mechanism 2039, and motor drive
means 2040. In the position A as indicated by a dashed line and extended
laterally in the main body 2, the cartridge 2012 is set and used. In the
position as indicated by a solid line and extended vertically in the main
body 2 and located outside the main body, the cartridge 2012 is replaced
with a new one. For replacement of the cartridge, the dispenser unit 2041
is turned to the replacing position B. An old cartridge 2012 is removed,
and a new cartridge 2012 is set in the cartridge set portion 2021.
Thereafter, the dispenser unit is turned to the position A and fixed
thereat.
Description to follow is how the toner cartridge 2012 is set to the
cartridge set portion 2021. As shown in FIG. 28, a user first turns the
dispenser unit 2041 to the replacing position B, and locates the toner
cartridge 2012 on the cartridge set portion 2021, as shown in FIGS. 25(a)
and 26, in a state that the first positioning means 2019 of the cartridge
is positioned above and directed horizontally. In this state, the toner
cartridge 2012 is axially moved forwardly (to the right in FIG. 16).
If the toner cartridge 2012 is a toner cartridge designed to be used
exclusively for the copying machine under discussion, the unlock cam 2014f
of the toner cartridge 2012 is placed facing the cut-out groove 2023c, and
the unlock cam 2014f is fitted into the cut-out groove 2023c. Accordingly,
the toner cartridge 2012 is allowed to move up to a preset position on the
axial path along which the tubular protrusion 2014g is fitted into the
circular hole 2022k of the cover 2022. If the cartridge containing the
incompatible or imitative toner, the unlock cam 2014f is placed not facing
the cut-out groove 2023c. Accordingly, the unlock cam 2014f cannot be
fitted into the cut-out groove 2023c, and hence the toner cartridge cannot
be moved up to the preset position. Thus, setting such cartridges to the
cartridge set portion 2021 is rejected. In other words, the user will not
set an incorrect toner cartridge to the cartridge set portion.
When the unlock 2014f is inserted into the cut-out groove 2023c, the cam
2014f pushes the lock 2022d to expel it out of the cut-out groove 2023c.
Then, the shutter 2023 is slidable in the circumferential direction. In
this state, if the toner cartridge 2012 is turned counterclockwise in FIG.
25(a) (the user turns it clockwise), the end 2014h of the guide member
2014d closer to the guide member 2014d comes in contact with the end 2023e
of the cartridge support 2023a closer to the shutter portion 2023b.
Accordingly, the shutter 2023 turns together with the toner cartridge
2012. With rotation of the shutter 2023, the opening 2022c of the cover
2022 is opened. One end 2018a of the shutter 2018 of the toner cartridge
2012 engages with the engaging part 2022m. As a result, if the toner
cartridge 2012 is turned, the shutter 2018 will not turn together with the
cartridge. In other words, the shutter 2018 turns relative to the toner
cartridge 2012, so that the toner supply port 2014c is opened. In this
way, both the shutters 2018 and 2023 turn in connection with the turn of
the cartridge 2012, and the toner supply port 2014c and the opening 2022c
automatically open. When the toner cartridge 2012 is turned, the guide
groove 2014e forming part of the guide member 2014d is fitted into the
concave portion 2022i of the guide member 2022h. The result is that the
toner cartridge 2021 is immovable in the axial direction.
The toner cartridge 2012 is then turned at a prescribed angle .alpha.. The
second positioning means 2020 is horizontally postured, so that the toner
cartridge 2012 is set in place. When the toner cartridge 2012 is set in
place, the toner supply hole 2014c and the opening 2022c are both opened.
Accordingly, toner is introduced from the toner cartridge 2012 into the
toner introducing portion 2017c of the reserve tank 2017, through the
toner supply hole 2014c and the opening 2022c. Finally, the dispenser unit
2041 is turned to set the toner cartridge 2012 to the position A. Here,
the setting of the toner cartridge is complete.
When the toner in the cartridge 2012 is used up and the cartridge must be
replaced with a new one, a user turns the dispenser unit 2041 to set the
cartridge 2012 to the replacing position B. Then, he turns clockwise the
cartridge 2012 till the first positioning means 2019 is set horizontally
in FIG. 25(a). In this state, the guide member 2014d slips out of the
concave portion 2022i of the guide member 2022h, and the shutter 2023
turns to open the opening 2022c. The shutter 2018 also moves relative to
the toner cartridge to close the toner supply port 2014c.
Then, the toner cartridge 2012 is axially moved to the left in FIG. 16, and
then the toner cartridge 2012 may be removed. With the movement of the
toner cartridge 2012, the unlock cam 2014f gets out of the cut-out groove
2023c, and the lock 2022d is fitted into the groove 2023c. The result is
that the shutter 2023 is locked to be immovable in the circumferential
direction. The user discards the empty toner cartridge and sets a new
toner cartridge 2012 filled with toner. The setting operation is the same
as mentioned above, and hence no further description will be given here.
It should be understood that in the description thus far made, the present
invention is applied to the color copying machine, but it may be applied
to other image forming apparatuses.
As seen from the foregoing description, the empty sensor is disposed so as
not to be little influenced by the leaked toner, and arranged so as to
sense such an amount of left toner as to allow a prescribed number of
copies. The amount of the toner left can be accurately sensed. The
accurate sensing of the left toner leads to improved reliability of the
left toner sensing, and provides an optimum timing of the cartridge
replacement.
Further, the left toner sensing is automatically removed in synchronism
with the loading of the toner cartridge. Therefore, the left-toner removal
is quick, smooth and reliable.
Additionally, a two-contact switch is used for the switch removing the
left-toner sensing. The two contacts of the switch are alternately turned
on when the toner cartridge is loaded and removed. The contact being in an
on state is stored in the nonvolatile memory of the copying machine. Upon
sensing of a state change of the on-state the contact, the empty or
left-toner sensing is removed and the replacement of the toner cartridge
is detected. With this prominent characteristic, if a user turns off the
power switch of the image forming apparatus at the time of cartridge
replacement, the empty sensing removal and the cartridge-replacement
detection can be surely performed.
Furthermore, the empty sensing is removed in response to a cartridge
loading signal. The empty sensor is inhibited from sensing an empty state
during a period from the empty sensing till a prescribed number of
dispensing operations are completed. The amount of toner left in the toner
cartridge is predicted on the basis of the result of counting the number
of dispensing operations. Therefore, the reliability of the dispensing
system is remarkably improved.
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